Two private investigators have been charged in federal court in connection with a Hewlett-Packard spying scandal in which they allegedly used false identities to obtain the phone records of board members, employees and journalists, court records show.

Matthew DePante and his father, Joseph DePante, were charged in U.S. District Court in San Jose on Thursday with conspiracy to commit Social Security fraud, the latest development in a corporate spying scandal that ruptured the reputation of one of Silicon Valley's most revered companies.

They were named in a court document known as an information, which in federal court typically signifies that a defendant intends to plead guilty. Court records released Monday show that both men are due to change their plea on Wednesday before U.S. District Judge Lucy Koh in San Jose.

The defendants were subcontractors who ran a private investigation company called Action Research Group in Melbourne, Fla., and were hired for the secret operation, authorities said.

The two used a practice known as pretexting by directing other investigators, posing as account holders or employees of phone companies, to fraudulently obtain personal information including phone numbers, date of birth, Social Security numbers, call logs, billing records and subscriber information, authorities said.

As part of the investigation, HP and private investigators obtained confidential information belonging to HP board members and employees, reporters for Cnet, the Wall Street Journal, the New York Times and the journalists' families, prosecutors said. The case began when then-CEO Carly Fiorina and other directors began looking into leaks of board deliberations to journalists.

In 2007, a Santa Clara County Superior Court judge dismissed charges against then-HP Chairwoman Patricia Dunn in connection with the case. The move came after the state attorney general's office reduced charges against several other defendants, including Matthew DePante.